WASHINGTON -- U.S. Secretary of State John Kerry, in separate calls with the presidents of Armenia and Azerbaijan on June 30, noted the cease-fire in the breakaway region of Nagorno-Karabakh was largely holding and urged the leaders to avoid tensions.

The State Department said Kerry asked Armenian President Serzh Sarkisian and Azerbaijani President Ilham Aliyevo to fulfill confidence-building measures and other commitments they made to advance the peace process at a May 16 meeting in Vienna and at a June 20 meeting in St. Petersburg.

Sarkisian's office said the Armenian president and Kerry discussed developments in efforts by the OSCE's Minsk Group to resolve the conflict.

The discussions came a day after German Foreign Minister Frank-Walter Steinmeier said that the fragile cease-fire between Armenian and Azerbaijani forces in Karabakh must be strengthened to reduce the chances of fighting breaking out as it did earlier this year, when dozens were killed and injured.

The territory, populated mainly by ethnic Armenians, declared independence from Azerbaijan in a 1988-94 war that killed an estimated 30,000 people.